Unitary self-energizing oil control ring

ABSTRACT

Oil control piston rings which have self-expanding properties eliminating the necessity for backup expander rings. The expansion is obtained by springs which are part of the ring structure. The preferred arrangements have hairpin springs projecting inwardly from the oil ring which, in use, extend through the oil drainage slots of the piston ring groove.

ite States atent Inventor Harold E. McCormick Ballwin, Mo.

Appl. No. 876,889

Filed Nov. 14, 1969 Patented Dec. 7, 1971 Assignee Ramsey CorporationSt. Louis, Mo.

UNITARY SELF-ENERGIZING 01L CONTROL RING 8 Claims, 11 Drawing Figs.

US. Cl 277/151, 277/219 Int. Cl F16] 9/06 Field of Search 277/149,

[56] References Cited UNITED STATES PATENTS 1,547,919 7/1925 Huhn277/151 2,203,154 6/1940 Johnston 277/151 X 2,520,369 8/1950 McFall277/151 X 3,006,704 10/1961 Guyer 277/216 X Primary Examiner-Robert 1.Smith Attorney-Hill, Sherman, Meroni, Gross & Simpson ABSTRACT: Oilcontrol piston rings which have self-expanding properties eliminatingthe necessity for backup expander rings. The expansion is obtained bysprings which are part of the ring structure. The preferred arrangementshave hairpin springs projecting inwardly from the oil ring which, inuse, extend through the oil drainage slots of the piston ring groove.

UNITARY SELF-ENERGIZING OIL CONTROL RING BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to the packing ring orpiston ring art, and especially to internal combustion engine piston oilcontrol rings with built-in spring properties.

2. Description of the Prior Art Oil control rings for internalcombustion engine pistons have heretofore required backup expansionrings in order to control the load on the cylinder wall for maintainingthe proper functioning of the ring as, for example, in the Mahew andAnderson US. Pat. No. 3,281,156 dated Oct. 25, I966 and the Anderson US.Pat. No. 3,378,268 dated Apr. I6, 1968.

SUMMARY OF THE INVENTION The present invention now eliminates thenecessity for separate expansion rings for oil control rings andprovides a unitary self-energizing oil control ring having its ownbuilt-in spring capacity.

According to the invention, an oil control ring, preferably of theslotted channel type, is equipped with leaf or hairpin springsprojecting radially inward from the channel through the oil drainageslots or holes in the bottom of the oil ring groove of the piston. Whileit is preferred to provide diametrically opposed pairs of hairpinsprings on the oil control ring, in some instances the spring may belocated only at the split ends of the ring. The spring leaf itself isintegral with or attached to the vertical wall of the channel, and indeep groove installations the spring may be convoluted within theconfines of the ring groove to afford sufficient expansion force withoutprojecting through the oil drainage hole or slot in the bottom of thering groove.

It is then an object of this invention to provide a packing ring withits own built-in expansion spring.

A further object is to provide a one-piece, self-energizing oil controlring for pistons.

Another object of the invention is to provide an oil control ring forinternal combustion engine pistons which has hairpin spring meansexpanding the ring.

A specific object of the invention is to provide a channeltype oilcontrol ring in a plurality of segments joined by hairpin-type expansionsprings.

A still further object of the invention is to provide a onepiece, splitchannel-type oil control ring with a ring expanding hairpin spring atthe split ends thereof.

Other and further objects of this invention will be apparent to thoseskilled in this art from the following detailed descriptions of theannexed sheets of drawings which, by way of preferred embodiments, showseveral forms of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of aself-energizing oil control ring of this invention;

FIG. 2 is a side view of the ring of FIG. 1 taken along the line II-IIofFlG. 1;

FIG. 3 is an enlarged fragmentary side view taken along the line III-Il1of FIG. 1;

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is a cross-sectional view taken along the line V-V of FIG. I, andshowing the ring mounted in the oil ring groove of an internalcombustion engine piston in an engine cylinder;

FIG. 6 is a transverse cross-sectional view taken along the line VI-VIof FIG. 5;

FIG. 7 is a plan view of a modified oil ring of this invention;

FIG. 8 is a plan view of another modified oil ring of this invention;

FIG. 9 is a side elevational view of the ring of FIG. 8 taken along theline IX-IX of FIG. 8;

FIG. 10 is an enlarged cross-sectional view taken along the line X-X'ofFIG. 8;

FIG. 11 is a plan view of a still further modified oil ring of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The oil control ring 10 ofFIGS. 1-6 is a split, rolled steel annulus of generally U-shaped crosssection. The ring 10 has top and bottom radial or sidewalls l1 separatedby an upstanding peripheral wall 12 for most of the circumference of thewalls 11. The upstanding wall 12 has circumferential slots 13 at spacedintervals therearound. Rounded peripheral beads 14 project radiallyoutward from the wall 12 in spaced parallel relation and, as indicated,are at the junctions between the walls 11 and 12. The ring 10 thus hasan outwardly opening channel 15 between the beads 14 on the outer faceof the upstanding wall 12 and an inwardly opening deeper channel 16 onthe inner face of the wall 12. The slots 13 in the walls 12 provide forfree flow of oil between the channels 15 and 16.

As shown in FIG. 1, the ring 10 has diametrically opposite gaps 17 and18 at which the sidewalls 11 are circumferentially separated. Adjacentthe gap 17, the upstanding wall 12 is separated from the walls 11 anddirected radially inward therefrom to provide a pair of hairpin leafsprings 19 and 20. Thus, the wall 12 on one side of the gap 16 and inspaced relation from the gap is directed radially inward at 19a, then iscurved outwardly at 19b, and next terminates in a radial outward leg 19caligned with the gap 17. Similarly, the wall 12 on the other side of thegap 17 is directed radially inward at 20a in spaced relation from thegap, then is bent outwardly at 20b and terminates in a leg 200, alsoaligned with the gap. The legs 19c and 200 abut each other. Thesidewalls 11 project circumferentially beyond the legs 19a and 20a toterminate at the gap 17.

Similarly, the upstanding wall 12 is separated from the walls 11 onopposite sides of the gap 18. However, at the gap 18 a single, butmultiple leg, hairpin or wave leaf spring 21 is provided. On one side ofthe gap 18 the wall 12 is directed radially inward at 21a in spacedrelation from the gap, is thence turned outwardly at 21b to a radiallyoutwardly directed leg 210, which in turn is curved inwardly at 21d inthe gap 18 to a radially inwardly directed leg 2le curved at 21f at itsinner end and then directed radially outward at 21 to the wall 12 on theopposite side of the gap 18 in spaced relation from the gap. The singlespring 21 acts in the same manner as the abuttedtogether springs 19 and20 but, of course, the curved portion 21d of this spring serves toconnect the ring portions on opposite sides of the gap 18, and aone-piece ring is thus provided.

Briefly, the ring 10 may be considered as two semicircular U-shapedchannel segments in circumferentially spaced relation to provide gapstherebetween, and connected at one gap by a multiple-leg, radiallydirected leaf spring, and being split at the other gap where a pair ofradially directed abutting leaf springs control the gap.

As shown in FIGS. 5 and 6, the oil control ring 10 is mounted in the oilring groove 22 of an engine piston 23 mounted in an engine cylinder 24.The groove 22 has radially directed top and bottom sidewalls 25 and anaxially directed backwall or bottom 26. This bottom 26 hascircumferential slots 27 therethrough to accommodate free drainage ofoil for free flow of oil between the groove 22 and the interior of thepiston 23, as is customary in oil ring grooves.

The sidewalls 11 of the ring 10 fit freely between the sidewalls 25 ofthe groove 22, and the beads 14 of the ring 10 ride on the cylinder wall24. The channel 15 of the ring 10 thus is closed on its outer face bythe cylinder wall 24, while the channels 16 open to the slots 27 of thepiston, while, of course the slots 13 of the ring connect the channels15 and 16.

The springs 19, 20 and 21 project freely through the piston slots 27 andare effective to expand the ring 10 into proper seating engagement withthe cylinder 24. In operation the springs 19 and 20 are abutted togetherat the split gap 17 of the ring, and, together with the spring 21, arecircumferentially contracted so as to exert the expanding force on thering. The legs or fingers of the springs 19, 20 and 21 can be of anysuitable length to provide the desired spring force, and in operationthe gaps 17 and 18 are substantially closed.

The ring can be formed from a single ribbon or strip of steel, rolled tothe indicated channel shape and provided with reduced width sections atspaced intervals to form the springs.

The modified ring 10a of FIG. 7 is identical with the ring 10 of FIGS.1-6, with the exception that the two separate springs 19 and 20 arereplaced with a single spring 30 which is the same as the spring 21. Thering 100 is thus continuous, since the spring 30, like the spring 21,has a connecting loop portion 30d between legs 30c. Thus, the sides ofthe gap 17 are connected through the spring 30 instead of being split,as in the ring 10. The ring 10a has advantages in certain installationsto avoid buckling of the expander springs.

The ring 100 may be formed in the same manner as the ring 10, exceptthat the loop-forming portion 30d of the spring 30 would have abuttingends welded together.

The modified ring 10b of FIGS. 8-10 is substantially identical with thering 10, except that the channel portions are formed as separatesegments and have a cast or forged body. The separate segments areconnected by separate springs which are welded or otherwise fastened tothe ends of the segments.

As shown in FIGS. 8-10, the ring 1012 is composed of a pair ofsemicircular body segments 40, each having radially directed sidewalls41 separated by an upstanding peripheral wall 42 which hascircumferential slots 43 therethrough. Peripheral beads 44 projectoutwardly from the wall 42 on opposite sides of the slots 43 and extendcircumferentially around the entire segment. It will be noted from FIG.10 that these beads 44 are axially inward from the sidewalls 41. Anoutwardly opening channel 45 is provided between the beads 44 on theouter face of the wall 42, and an inwardly opening channel 46 isprovided between the sidewalls 41 on the inner face of the wall 42.

The segments 40 are separated circumferentially by gaps 47 and 48 indiametrically opposed relation. The upstanding wall 42 of each segment40 terminates in spaced relation from each gap 47 and 48, as indicatedat 42a, so that the top and bottom radial walls 41 will projectcircumferentially beyond the walls 42 to the gaps 47 and 48.

Hairpin leaf springs 49 and 50 are provided at the gap 47, and thesesprings have the same leg arrangements as the springs 19 and 20 of thering 10, and are similarly identified at 49a, 49b, 49c, 50a, 50b and50c. In addition, however, the springs 49 and 50 have out-turned legs49d and 50d, respectively, on the outer ends of the legs 49a and 50a,which overlie the walls 42 of the respective segments 40 and are securedthereto, as by means of spot welds or the like.

A spring 51 similar to the spring 21 of the ring 10, and having theconvoluted legs and hump or curved portions 51a-51g, also has out-turnedlegs 51h and 511' on the outer ends of the legs 51a and 51g overlyingthe walls 42 of the respective segments 40 and secured thereto, as byspot welds or the like.

Alternately, the springs 49, 50 and 51 could be secured to the ringsegments 40 by means of mechanical fastening devices, interlocking tabsor the like.

The ring 10b will function in the same manner as the ring 10, and couldalso be made continuous, like the ring 10a, by replacing the springs 49and 50 with a single spring such as 30 of FIG. 10a.

In the modification of FIG. 11 the ring 100 is the same as the ring1012, except that the springs 49 and 50 are omitted, and the gap 47 is afree gap, with the upstanding walls 42 of the segments 40 extending tothe gap. In FIG. 11 parts identical with the ring 10b of FIGS. 8-10 havebeen marked with the same reference numerals, and it will be understoodthat the rings 10b and 100 differ only in the omission of the springs 49and 50 and the extensions of the walls 42 of the segments 40 up to thegap 47. The ring 10c is useful in applications where the single spring51 will supply suflicient expanding force.

From the above descriptions it will, therefore, be clear that rings suchas 10, 10a, 10b and of this invention may be further modified andrearranged as suggested above, and that the invention provides oilcontrol rings with ample spring loading without separate expandersprings or the like. The rings of this invention are thus unitary andself-energizing.

What I claim is:

1. A packing ring for installation in a ring groove to seal a contiguoussurface which comprises an annular member having two circumferentialgaps accommodating expansion and contraction, a one-piece leaf springsecured at opposite ends to said member in spaced relation to oppositesides of one of said gaps and extending radially inward from the member,and a pair of abutting leaf springs each secured in spaced relation toopposite sides of the other of said gaps and extending radially inwardfrom said member, said leaf springs cooperating to expand the memberagainst the contiguous surface and said pair of abutting leaf springsadapted to be separated for installation of the member in a ring groove.

2. A piston ring which comprises an annular body member having at leastone gap in the periphery thereof accommodating contraction and expansionof the body member, and a hairpin spring means secured at its ends tosaid body member in spaced relation from opposite sides of said gap andextending inward from said body member to curved inner ends spacedradially from the body member and thence extending radially outward to acurved outer end lying in the gap and effective to expand the bodymember to widen said gap.

3. An oil control piston ring comprising a ring body of channel-shapedcross section having an upstanding peripheral wall, spaced parallelbeads projecting radially from the outer periphery of said wall definingan outwardly opening channel therebetween and top and bottom sidewallsprojecting radially inwardly from said upstanding wall defining aninwardly opening channel therebetween, circumferentially spaced slotsthrough said upstanding wall joining said outwardly opening and inwardlyopening channels, said ring having at least one gap therethroughaccommodating radial expansion and contraction of the ring, saidupstanding wall of the ring terminating in spaced circumferentialrelation from each side of said gap, and hairpin spring means carried bysaid ring projecting radially inward at the terminal ends of saidupstanding wall and bridging said gap for expanding the ring.

4. The oil control piston ring of claim 3 wherein the spring means is aconvoluted leaf spring with ends attached to the ring body on oppositesides of the gap.

5. An oil control piston ring comprising a split ring body ofchannel-shaped cross section adapted to expand from a closed gapposition at the split ends thereof, said ring having radial walls heldin axially spaced relation by an upstanding wall, said upstanding wallbeing separated from said radial walls in circumferentially spacedrelation from both sides of the gap and directed radially inward andthence radially outward to provide a hairpin spring increasing the widthof the gap between the split ends to expand the ring.

6. The packing ring of claim 5 wherein the hairpin spring is integralwith said upstanding wall.

7. A piston ring which comprises a plurality of ring segments havinggaps therebetween and upstanding peripheral walls terminating incircumferentially spaced relation from both sides of the gaps, andhairpin springs secured to the terminal ends of the upstanding walls ateach gap and extending radially inward to curved inner ends spacedradially from the segments and thence extending radially outward fromsaid inner ends to provide leaf springs effective to expand the ring.

8. The piston ring of claim 7 wherein the ring segments havechannel-shaped cross sections and the hairpin springs are integrallyconnected with the upstanding walls of the channels on each side of eachgap.

1. A packing ring for installation in a ring groove to seal a contiguoussurface which comprises an annular member having two circumferentialgaps accommodating expansion and contraction, a one-piece leaf springsecured at opposite ends to said member in spaced relation to oppositesides of one of said gaps and extending radially inward from the member,and a pair of abutting leaf springs each secured in spaced relation toopposite sides of the other of said gaps and extending radially inwardfrom said member, said leaf springs cooperating to expand the memberagainst the contiguous surface and said pair of abutting leaf springsadapted to be separated for installation of the member in a ring groove.2. A piston ring which comprises an annular body member having at leastone gap in the periphery thereof accommodating contraction and expansionof the body member, and a hairpin spring means secured at its ends tosaid body member in spaced relation from opposite sides of said gap andextending inward from said body member to curved inner ends spacedradially from the body member and thence extending radially outward to acurved outer end lying in the gap and effective to expand the bodymember to widen said gap.
 3. An oil control piston ring comprising aring body of channel-shaped cross section having an upstandingperipheral wall, spaced parallel beads projecting radially from theouter periphery of said wall defining an outwardly opening channeltherebetween and top and bottom sidewalls projecting radially inwardlyfrom said upstanding wall defining an inwardly opening channeltherebetween, circumferentially spaced slots through said upstandingwall joining said outwardly opening and inwardly opening channels, saidring having at least one gap therethrough accommodating radial expansionand contraction of the ring, said upstanding wall of the ringterminating in spaced circumferential relation from each side of saidgap, and hairpin spring means carried by said ring projecting radiallyinward at the terminal ends of said upstanding wall and bridging saidgap for expanding the ring.
 4. The oil control piston ring of claim 3wherein the spring means is a convoluted leaf spring with ends attachedto the ring body on opposite sides of the gap.
 5. An oil control pistonring comprising a split ring body oF channel-shaped cross sectionadapted to expand from a closed gap position at the split ends thereof,said ring having radial walls held in axially spaced relation by anupstanding wall, said upstanding wall being separated from said radialwalls in circumferentially spaced relation from both sides of the gapand directed radially inward and thence radially outward to provide ahairpin spring increasing the width of the gap between the split ends toexpand the ring.
 6. The packing ring of claim 5 wherein the hairpinspring is integral with said upstanding wall.
 7. A piston ring whichcomprises a plurality of ring segments having gaps therebetween andupstanding peripheral walls terminating in circumferentially spacedrelation from both sides of the gaps, and hairpin springs secured to theterminal ends of the upstanding walls at each gap and extending radiallyinward to curved inner ends spaced radially from the segments and thenceextending radially outward from said inner ends to provide leaf springseffective to expand the ring.
 8. The piston ring of claim 7 wherein thering segments have channel-shaped cross sections and the hairpin springsare integrally connected with the upstanding walls of the channels oneach side of each gap.